1. Field of the Invention
The present invention relates to a semiconductor device such as a power module.
2. Description of Related Art
A power module is a device in which paired switching elements are connected in series to a power supply, and an output is obtained from between the paired switching elements. Such a power module is used in, for example, an inverter circuit constituting a driving circuit for driving an electric motor.
The inventors have developed a new method of manufacturing a power module. Specifically, a plurality of sheet members, on which predetermined processing is performed in advance, are prepared. Each of the sheet members includes a thermoplastic resin film. The predetermined processing includes etching for forming a circuit, hole processing for forming a hole, and metal paste filling for forming a connection metal member such as a via. A component hole for receiving an electronic component is formed in a predetermined sheet member.
The plurality of sheet members are stacked. In this process, each of a high-side switching element and a low-side switching clement is received in a predetermined component hole. These two switching elements are disposed to face each other at intervals in atop-bottom direction. Hot pressing is performed in a state where all the sheet members are stacked. Thus, it is possible to obtain a power module in which the high-side switching element and the low-side switching element are provided.
In such a power module, a connection metal member, which is electrically connected to a main electrode formed on the upper surface side of each of the switching elements, is disposed on the upper surface of the switching element. In addition, a connection metal member, which is electrically connected to a main electrode formed on the lower surface side of each of the switching elements, is disposed on the lower surface of the switching element. In such a power module, when a plurality of sheet members stacked in a manufacturing process are hot-pressed together, large stress is applied to each of the switching elements through the connection metal members, and therefore, there is a possibility that breakage may occur in the switching element.